#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
int main(int argc ,char *argv[])
{
    int fd = open(argv[1],O_WRONLY);   
    if(fd<0)
        printf("open error!\r\n");
    char data = atoi(argv[2]);
    int ret = write(fd,&data,1);
    if(ret<0)
        printf("write error!\r\n");
    close(fd);
    return 0;
}